The thread on novels and RPGs got me thinking of this.
I oft wondered if D&D's Astral Projection spell, and later material which noted that you create a new body when entering another dimension, was inspired by either Carter's ability of astral projection which had him creating a new body on Barsoom? Or a similar technique used in at least one of Lovecrafts books?
Or were both inspired by something older?
It's inspired by real world occult/parapsychology/new age stuff. Which had been cyclically popular and had something of a boom again in the late 60s, which is presumably why EGG included it
My own father said he once did it back then, after reading a book, and it scared him so much he went back into his body almost immediately and never tried it again. He never did drugs and was atheist, so I dunno.
Yeah, I think it's mostly based on the new-age notions of astral travel, born from 19th century theosophy and spiritism.